1. Field of the Invention
The present invention relates to rapid acquisition and demodulation systems. More particularly, the present invention relates to a high speed, high performance acquisition system which is designed to operate in real time to receive, acquire and lock onto a received PN coded signal by first processing a preamble or header before receiving a long PN code for high performance gain.
2. Description of the Prior Art
A high processing gain acquisition and demodulation system implies that there are a very large number of PN chips included in each data symbol time, thus, high performance systems have less energy per chip. It is necessary to process the high performance PN coded information over a very large number of data symbol times to build up a sufficient signal to noise ratio to acquire the incoming signal.
It has been suggested to use matched filters and/or parallel correlations to enhance the build up of the signal to noise ratio of the PN coded signals over fewer data symbol times. It is presently not commercially feasible to build parallel correlators or matched filers with enough taps to acquire the received high performance system PN signal in real time.
Thus it would be highly desirable to provide an apparatus or system capable of acquiring high speed, high performance, high processing gain PN coded signals in real time.